Spatial-temporal analysis of climate change impact on viticultural regions Valencia DO and Goriška Brda

Abstract

Changes in viticulture, especially in changing position of vineyards and introducing new grape varieties, are becoming a reality. Vine is highly sensitive to climate, particularly temperature changes, which can be reflected in shifts of phenological stages and differences of wine characteristics, which clearly show recent impact of climate change in viticulture. Moreover, recent climate change developments have affected irrigation and water management in viticulture worldwide, which will have to adapt in order to maintain yield quality and quantity in the future. The spatial-variability of climate conditions has been observed in viticulture areas all over the world in order to gain more data about historical and future climate conditions. Numerous analyses were conducted concerning climate change in viticulture in regional scales. However, only a few were made addressing the impact of climate change on viticulture in local scale, such as this thesis. Using the local scale is crucial for the assessment of viticultural potential that is determined by relief, soil, climate and lithology. Analysis of viticultural potential in viticulture is essential for the purpose to collect the necessary data for viticultural zoning. Using this data, we can achieve greater yield quality, which is the most important criteria in viticulture. The purpose of this research is to provide the spatial-temporal assessment of climate change during the last five decades and future scenarios, along with its impact on viticulture in two viticultural regions: Valencia DO (39° 37'10 N, 0° 36'2 W) is located in the eastern Spain and Goriska Brda in western Slovenia (46° 0' 19 N, 13° 32' 42 E). Both study sites are located less within 70 km from the Mediterranean coast and share similar topographic characteristics. We used the meteorological and soil parameters retrieved from selected weather stations, with the future climate models, under RCP4.5 and RCP8.5 scenarios, using Worldclim and Euro-Cordex datasets. Spatial-temporal study was conducted by using bioclimatic indices Huglin, Winkler and Dryness index, suggesting the most conducive grape varieties in terms of production and quality according to the local climate conditions. Moreover, we assessed the future water requirements (WR) for Tempranillo, Bobal and Moscatel in Valencia DO by using evapotranspiration method by Blaney-Criddle. In Goriska Brda, were chosen fourteen environmental factors, which represent relief, climate and soil of the viticulture area, which were used to determinate homogeneous viticultural zones. Each homogeneous viticultural zone was described in terms of its viticultural potential, which expresses the types of wine that can be produced according to its ecological suitability. The spatial distributions of the environmental parameters were achieved by using GIS-based multicriteria methodology. The temperature, evapotranspiration and bioclimatic indices trends sites have been growing during observation period in both study sites and are estimated to rise in the future, according to elaborated climate models. The climatic parameters indicated high spatial-temporal variability: the rise of temperature was higher in the areas further away from the Mediterranean Sea, with less sea influence. Nevertheless, higher temperature increase is expected in Valencia DO. The average temperature under projected period 2071-2100 compared to the reference period 1985-2014 indicated the increase of 1.58°C (RCP4.5) and 3.43°C (RCP8.5) in Goriska Brda and 1.67°C (RCP4.5) and 3.61°C (RCP8.5) in Valencia DO. The precipitation trend demonstrated almost no difference by 2100 in Goriska Brda site in contrast to Valencia DO site, showing negative trend: up to 83.5mm under RCP8.5 scenario. According to the viticultural potential in Goriska Brda, there were defined three zones with different viticultural potential, indicating the wine types which can be produced: a zone suitable for quality white wines and